1. Technical Field
The present invention relates to a semiconductor device.
2. Related Art
Semiconductor devices so far developed include those disclosed in Japanese Laid-open patent publications No. 2001-102576 and No. 2001-352063. The semiconductor device according to these publications is a vertical MOSFET, which includes a plurality of unit cells, respectively consisting of a back-gate region (body contact region) provided in a semiconductor substrate and a source region disposed so as to surround the back-gate region. Each of the unit cells is surrounded by a gate electrode buried in a trench formed in the semiconductor substrate.